The present invention is related to the field of volume determination of comestible products, i.e., meat cuts and whole animal carcasses. More specifically, the present invention is directed towards methods and devices for the automated high-speed volumetric determination of content values, including fat content, in various comestible products.
Meat, poultry and fish producers are in the business of converting live animals into consumable products for humans. These producers experience thin profit margins and are constantly in search of processes that can increase the quality of the product offered to consumers.
One attribute that determines processed food quality is fat content. For most meat, poultry and fish products for example, reduced-fat cuts are more desirable and, as such, more profitable for the producers. Unfortunately, fat content for whole animal products or for processed animal parts is difficult to determine since most of the contained fat is not exposed at the surface of the whole animal carcass or processed cut. The industry needs a reliable way of determining fat content for processed meat, fish and poultry without subjecting the cut or carcass to destructive processes.
It is relatively easy to precisely measure the weight (and determine the mass) of meat, poultry and fish. Since fat and lean densities are well known in these industries, the percentage of fat content can be precisely determined if the exact volume of the cut or carcass could be measured. Unfortunately, the industry has not been able to realize a reliable approach for performing non-contact, non-destructive volumetric measurement, particularly in a mass production environment.
Previous methods for determining the fat content of cuts of meat required measuring the volume of the cuts of meat by compressing the tissue to a preselected state and directly measuring the volume. More specifically, these previous methods generally used a piston or a press plate to apply a substantial force to the meat sample in order to compact the meat sample and measure the volume. Examples are shown in U.S. Pat. Nos. 3,282,115 to Taylor et al.; 3,455,168 to Taylor et al.; U.S. Pat. No. 3,487,698 to Leger et al.; and U.S. Pat. No. 4,449,406 to van Haren. There are several drawbacks to these previous approaches for determining the volume of a meat sample. For example, the previous methods are time-consuming, are not well suited for modern automated food production facilities and do not provide a non-contact means for measuring the volume of the comestible product. In addition, these methods do not accurately measure the volume of every cut of meat, nor do they provide a means for determining the volume, and ultimately the fat content, of a whole animal carcass.
Another volumetric method for determining the fat content of an object consists of two connected chambers. In this method, the object to be measured is enclosed in the first chamber, which is connected to a second chamber of known volume. Pressure measurements are then made in the chamber housing the object both before and after a valve is opened connecting the two chambers. Knowing the two pressures and the incremental volume of the second chamber allows one to calculate the volume of the object in the first chamber by Boyle""s law. Examples of these two chamber techniques are shown in U.S. Pat. Nos. 5,105,825 to Dempster and U.S. Pat. No. 5,450,750 to Abler.
While a two-chamber approach to volumetric measurement can be a useful way to compute the volume and ultimately the fat content, of human subjects, this approach does not lend itself to the high-speed requirements of modern food processing facilities because of cost and space issues. The two-chamber approach is simply not feasible for mass production facilities because each measurement chamber requires a second connected chamber of known volume. With the large number of comestible products being produced, it would be desirable to provide an automated high-speed system for determining the volume, and ultimately the fat or other content values, of comestible products that address these and other shortcomings of the existing techniques.
The present invention is a system that performs content analysis on comestible products using volumetric determination with a single chamber technique in a mass production environment. The content value determination system includes a conveyor system, a system for weighing the comestible products interposed along the path of the conveyor, a volumetric determination station that consists of a plurality of receiving chambers, and a control module. In this embodiment, each receiving chamber is equipped with a pressure sensor and a mechanical system for modifying the volume of the chamber. In addition, both the pressure sensors and the volume modification system of each receiving chamber are operably connected to the control module.
In a preferred embodiment, the system includes an X-ray emitter and collector that provide X-ray images as the comestible products move along the path of the conveyor. The X-ray emitter and collector are operably connected to the control module, where the X-ray images are stored and used to determine the percentage of each comestible product that is bone material. This feature of the invention improves the overall accuracy of the content value determination for boned objects.
In another embodiment of the present invention, a volumetric determination device is provided. The volumetric determination device includes a single selectively sealable volumetric measurement chamber designed to enclose a comestible food product, such as a meat cut or whole animal carcass. The volumetric measurement chamber is equipped with a pressure sensor that is operably coupled to a control module. The pressure sensor measures the pressure inside the volumetric measurement chamber both before and after the volume inside the chamber has been modified by a known amount. A mechanical system is operably connected to the volumetric measurement chamber and provides a method for changing the volume of the chamber. In this embodiment, the volume of the comestible product can be computed by the control module based upon the initial pressure inside the chamber, the final pressure and the known change in volume of the chamber.
In a method in accordance with the present invention, a content value of a comestible product is determined by an automated process. The comestible products are placed onto a conveyor system. While moving along the conveyor system, the comestible products are weighed by a weighing system interposed along the path of the conveyor. The weighing system is operably connected to a control module, which records the weight of each comestible product. The conveyor system transports the comestible products to a volumetric determination station that consists of multiple receiving chambers. Each individual comestible product is encompassed in one of the receiving chambers and the initial pressure inside the chamber is recorded. The volume of the chamber is then modified by a known amount by a mechanical system and a second pressure is recorded. The control module, which is operably connected to each receiving chamber, then computes the volume of each of a plurality of comestible products based upon the change in pressure inside the chambers and the known modified volume. Once the volume of the comestible product is known, the control module can compute the fat content, or other content values, of the comestible product based upon the weight, volume and other characteristics of that product.
The present invention defines a process for determining the volume of any comestible product without exposing the product to fluids, chemicals, or heat. The invention utilizes the simple relationship between pressure and volume of a gas (commonly known as Boyle""s Law and expressed as P1*V1=P2*V2) to compute the volume of a solid object. This method is especially useful in whole poultry production where the carcass cavity is mostly hidden from visual and other scanning methods.
In another embodiment of the invention, a method for determining percentage bone content in a comestible product is provided by subjecting the comestible product to non-visible radiation. An amount of absorbed non-visible radiation by the comestible product is detected and an internal image of at least one bone structure of the comestible product based upon the detected absorbed radiation is constructed. The image is transmitted to a control module that calculates a percentage of bone material in the comestible product based upon the internal image of the at least one bone structure.
The products referred to in this invention can be comestible products such as whole carcasses or cuts from carcasses of beef, pork, sheep, chickens, turkeys or fish. The object to be measured is placed in an airtight chamber of known volume. The pressure in the chamber is recorded upon closure of the chamber. The volume of the chamber is modified (preferably decreased) by a known amount with a piston, bellows, or some other high-speed mechanical or electromechanical device, and the resultant chamber pressure is recorded. These values can be used to determine the precise volume of the object in the chamber.
The objects described herein are primarily cuts and carcasses of beef, pork, poultry and fish. However, the same techniques can be used in other industries including, but not limited to, fruits, vegetables, grains and other processed foods. In fact, any industry that depends on high-volume manufacturing or processing that wishes to determine the content value of a particular ingredient of an intermediate or finished product can utilize the methods and devices of the present invention.
In contrast to previous methods for determining the volume of a meat cut which measured the volume of the meat cut directly, the present invention is capable of precisely measuring the volume of a whole animal carcass. This is accomplished primarily by designing volumetric measurement chambers that are able to accommodate either a cut of meat or an entire carcass. Furthermore, the present invention is designed to measure the volume of an object by utilizing only a single measurement chamber, thus eliminating the need to have a second measurement chamber attached to the first chamber.